diff --git a/cpp/CHANGELOG.md b/cpp/CHANGELOG.md
index de7d8306fdc5a2618129115c95e376062dd5b019..1f0aedef855870c4c05e23489a8cb8f4216d8472 100644
--- a/cpp/CHANGELOG.md
+++ b/cpp/CHANGELOG.md
@@ -11,6 +11,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-553 - Refine cache code
 - MS-557 - Merge Log.h
 - MS-556 - Add Job Definition in Scheduler
+- MS-558 - Refine status code
 
 ## New Feature
 
diff --git a/cpp/src/db/DB.h b/cpp/src/db/DB.h
index 1de424ed78e28e92d865526bca4060c9120f9089..5fe6df491f2d57369bae477a03c120bcdfa1752c 100644
--- a/cpp/src/db/DB.h
+++ b/cpp/src/db/DB.h
@@ -15,12 +15,13 @@
 // specific language governing permissions and limitations
 // under the License.
 
+
 #pragma once
 
 #include "Options.h"
-#include "meta/Meta.h"
-#include "Status.h"
 #include "Types.h"
+#include "meta/Meta.h"
+#include "utils/Status.h"
 
 #include <string>
 #include <memory>
diff --git a/cpp/src/db/engine/EngineFactory.h b/cpp/src/db/engine/EngineFactory.h
index 906260b966244e1388b267cd5801206fae131a51..c3fb41addeee76e321e0a71f1f38d6a2679c86cf 100644
--- a/cpp/src/db/engine/EngineFactory.h
+++ b/cpp/src/db/engine/EngineFactory.h
@@ -15,10 +15,11 @@
 // specific language governing permissions and limitations
 // under the License.
 
+
 #pragma once
 
-#include "db/Status.h"
 #include "ExecutionEngine.h"
+#include "utils/Status.h"
 
 namespace zilliz {
 namespace milvus {
diff --git a/cpp/src/db/engine/ExecutionEngine.h b/cpp/src/db/engine/ExecutionEngine.h
index 417d002a21585dd29be138a1617ddef8865ebe45..5868f15d338a9615f3a3d6d141211661f104e21f 100644
--- a/cpp/src/db/engine/ExecutionEngine.h
+++ b/cpp/src/db/engine/ExecutionEngine.h
@@ -17,7 +17,7 @@
 
 #pragma once
 
-#include "db/Status.h"
+#include "utils/Status.h"
 
 #include <vector>
 #include <memory>
diff --git a/cpp/src/db/insert/MemManager.h b/cpp/src/db/insert/MemManager.h
index de6ee85ed179cb72e60090d77aa9cb865c523ef4..37f0548646ba5ec1d4b7817e9827b39965b7fcf6 100644
--- a/cpp/src/db/insert/MemManager.h
+++ b/cpp/src/db/insert/MemManager.h
@@ -18,7 +18,7 @@
 
 #pragma once
 
-#include "db/Status.h"
+#include "utils/Status.h"
 #include "db/Types.h"
 
 #include <set>
diff --git a/cpp/src/db/insert/MemManagerImpl.h b/cpp/src/db/insert/MemManagerImpl.h
index 9b503216a74f4fd360103baa93d8d04d8753b8a6..51e8f1044e0f8fff48d5b0089a0b2a93c855852e 100644
--- a/cpp/src/db/insert/MemManagerImpl.h
+++ b/cpp/src/db/insert/MemManagerImpl.h
@@ -18,10 +18,10 @@
 
 #pragma once
 
-#include "db/meta/Meta.h"
 #include "MemTable.h"
-#include "db/Status.h"
 #include "MemManager.h"
+#include "db/meta/Meta.h"
+#include "utils/Status.h"
 
 #include <map>
 #include <string>
diff --git a/cpp/src/db/insert/MemTable.h b/cpp/src/db/insert/MemTable.h
index a44318690060b58782c54c5bdf20e92c9f19cb78..def4a6dccaeb0d5380aec398df555bc1d369f7ce 100644
--- a/cpp/src/db/insert/MemTable.h
+++ b/cpp/src/db/insert/MemTable.h
@@ -18,9 +18,9 @@
 
 #pragma once
 
-#include "db/Status.h"
 #include "MemTableFile.h"
 #include "VectorSource.h"
+#include "utils/Status.h"
 
 #include <mutex>
 
diff --git a/cpp/src/db/insert/MemTableFile.h b/cpp/src/db/insert/MemTableFile.h
index d4b11cda7af501404382948e2f5fe8954e4724d8..5ac3e15ad29568da93d3d8c7b67f8a015e342a47 100644
--- a/cpp/src/db/insert/MemTableFile.h
+++ b/cpp/src/db/insert/MemTableFile.h
@@ -18,10 +18,10 @@
 
 #pragma once
 
-#include "db/Status.h"
-#include "db/meta/Meta.h"
 #include "VectorSource.h"
+#include "db/meta/Meta.h"
 #include "db/engine/ExecutionEngine.h"
+#include "utils/Status.h"
 
 
 namespace zilliz {
diff --git a/cpp/src/db/insert/VectorSource.h b/cpp/src/db/insert/VectorSource.h
index 5c44f580d2f9d12a33c6d14e486e5971b681f141..a0292181ce5b1d343e0c84d95f0314a9c1f9d0a1 100644
--- a/cpp/src/db/insert/VectorSource.h
+++ b/cpp/src/db/insert/VectorSource.h
@@ -18,10 +18,10 @@
 
 #pragma once
 
-#include "db/Status.h"
 #include "db/meta/Meta.h"
 #include "db/IDGenerator.h"
 #include "db/engine/ExecutionEngine.h"
+#include "utils/Status.h"
 
 
 namespace zilliz {
diff --git a/cpp/src/db/meta/Meta.h b/cpp/src/db/meta/Meta.h
index 755e0170f2c26aed799856db0151ae870dc0d222..ee4972ae6be73c53bff381239eed90c1fa2e4ff7 100644
--- a/cpp/src/db/meta/Meta.h
+++ b/cpp/src/db/meta/Meta.h
@@ -15,12 +15,13 @@
 // specific language governing permissions and limitations
 // under the License.
 
+
 #pragma once
 
 #include "MetaTypes.h"
 #include "db/Options.h"
-#include "db/Status.h"
 #include "db/Types.h"
+#include "utils/Status.h"
 
 #include <cstddef>
 #include <memory>
diff --git a/cpp/src/metrics/Metrics.h b/cpp/src/metrics/Metrics.h
index e298af7acf820a553cdbd4dc66069152ef34e5e0..30d6e68f525778b0b915a7006964cf5fcd3a2f8b 100644
--- a/cpp/src/metrics/Metrics.h
+++ b/cpp/src/metrics/Metrics.h
@@ -15,6 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
+
 #pragma once
 
 #include "MetricBase.h"
@@ -63,7 +64,7 @@ protected:
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 class CollectInsertMetrics : CollectMetricsBase {
 public:
-    CollectInsertMetrics(size_t n, engine::Status& status) : n_(n), status_(status) {
+    CollectInsertMetrics(size_t n, Status& status) : n_(n), status_(status) {
     }
 
     ~CollectInsertMetrics() {
@@ -87,7 +88,7 @@ public:
 
 private:
     size_t n_;
-    engine::Status& status_;
+    Status& status_;
 };
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/cpp/src/sdk/CMakeLists.txt b/cpp/src/sdk/CMakeLists.txt
index 6c3a68b8b888929f0c8e3c579083d98fafc87015..5d6a1ea465134c22c82434fd192f753a32664695 100644
--- a/cpp/src/sdk/CMakeLists.txt
+++ b/cpp/src/sdk/CMakeLists.txt
@@ -20,8 +20,6 @@
 
 aux_source_directory(interface interface_files)
 
-aux_source_directory(util util_files)
-
 include_directories(/usr/include)
 include_directories(include)
 include_directories(/usr/local/include)
@@ -42,12 +40,15 @@ set(grpc_service_files
 add_library(milvus_sdk STATIC
         ${interface_files}
         ${grpc_client_files}
-        ${util_files}
         ${grpc_service_files}
         )
 
 target_link_libraries(milvus_sdk
-        ${third_party_libs}
+        ${client_grpc_lib}
+        bzip2
+        lz4
+        snappy
+        zlib
         )
 
 install(TARGETS milvus_sdk DESTINATION lib)
diff --git a/cpp/src/sdk/examples/grpcsimple/src/ClientTest.cpp b/cpp/src/sdk/examples/grpcsimple/src/ClientTest.cpp
index abfc92cc0bbd7884fe3d203a315934dcf49a6808..f0f7cf529237738f0a7625b619e0daa21370f57b 100644
--- a/cpp/src/sdk/examples/grpcsimple/src/ClientTest.cpp
+++ b/cpp/src/sdk/examples/grpcsimple/src/ClientTest.cpp
@@ -36,10 +36,10 @@ const std::string TABLE_NAME = GetTableName();
 constexpr int64_t TABLE_DIMENSION = 512;
 constexpr int64_t TABLE_INDEX_FILE_SIZE = 1024;
 constexpr int64_t BATCH_ROW_COUNT = 100000;
-constexpr int64_t NQ = 100;
-constexpr int64_t TOP_K = 1;
+constexpr int64_t NQ = 5;
+constexpr int64_t TOP_K = 10;
 constexpr int64_t SEARCH_TARGET = 5000; //change this value, result is different
-constexpr int64_t ADD_VECTOR_LOOP = 1;
+constexpr int64_t ADD_VECTOR_LOOP = 10;
 constexpr int64_t SECONDS_EACH_HOUR = 3600;
 
 #define BLOCK_SPLITER std::cout << "===========================================" << std::endl;
diff --git a/cpp/src/sdk/grpc/ClientProxy.cpp b/cpp/src/sdk/grpc/ClientProxy.cpp
index 56ba1e2de6a6ba8c1a231900c9b7cd137c129b67..2a87f7f92948b5d4ef7fd7bc29524d064e2e6012 100644
--- a/cpp/src/sdk/grpc/ClientProxy.cpp
+++ b/cpp/src/sdk/grpc/ClientProxy.cpp
@@ -51,7 +51,7 @@ ClientProxy::Connect(const ConnectParam &param) {
 Status
 ClientProxy::Connect(const std::string &uri) {
     if (!UriCheck(uri)) {
-        return Status::Invalid("Invalid uri");
+        return Status(StatusCode::InvalidAgument, "Invalid uri");
     }
     size_t index = uri.find_first_of(':', 0);
 
diff --git a/cpp/src/sdk/include/Status.h b/cpp/src/sdk/include/Status.h
index 6dbc762c0a2987929827444b31cbb35cfc7f1d07..145d09d47a548eaf981be3bb5ea6387266c31fb0 100644
--- a/cpp/src/sdk/include/Status.h
+++ b/cpp/src/sdk/include/Status.h
@@ -19,7 +19,6 @@
 #pragma once
 
 #include <string>
-#include <sstream>
 
 /** \brief Milvus SDK namespace
 */
@@ -30,345 +29,61 @@ namespace milvus {
 */
 enum class StatusCode {
     OK = 0,
-// system error section
+    // system error section
     UnknownError = 1,
     NotSupported,
     NotConnected,
 
-// function error section
+    // function error section
     InvalidAgument = 1000,
     RPCFailed,
     ServerFailed,
 };
 
+using ErrorCode = StatusCode;
+
 /**
 * @brief Status for SDK interface return
 */
 class Status {
 public:
-    /**
-     * @brief Status
-     *
-     * Default constructor.
-     *
-     */
-    Status() = default;
-
-    /**
-     * @brief Status
-     *
-     * Destructor.
-     *
-     */
-    ~Status() noexcept;
-
-    /**
-     * @brief Status
-     *
-     * Constructor
-     *
-     * @param code, status code.
-     * @param message, status message.
-     *
-     */
-    Status(StatusCode code, const std::string &message);
-
-    /**
-     * @brief Status
-     *
-     * Copy constructor
-     *
-     * @param status, status to be copied.
-     *
-     */
-    inline
-    Status(const Status &status);
-
-    /**
-     * @brief Status
-     *
-     * Assignment operator
-     *
-     * @param status, status to be copied.
-     * @return, the status is assigned.
-     *
-     */
-    Status
-    &operator=(const Status &s);
+    Status(ErrorCode code, const std::string &msg);
+    Status();
+    ~Status();
 
-    /**
-     * @brief Status
-     *
-     * Move constructor
-     *
-     * @param status, status to be moved.
-     *
-     */
-    Status(Status &&s) noexcept ;
+    Status(const Status &s);
 
-    /**
-     * @brief Status
-     *
-     * Move assignment operator
-     *
-     * @param status, status to be moved.
-     * @return, the status is moved.
-     *
-     */
-    Status
-    &operator=(Status &&s) noexcept;
+    Status &
+    operator=(const Status &s);
 
-    /**
-     * @brief Status
-     *
-     * AND operator
-     *
-     * @param status, status to be AND.
-     * @return, the status after AND operation.
-     *
-     */
-    inline
-    Status operator&(const Status &s) const noexcept;
+    Status(Status &&s);
 
-    /**
-     * @brief Status
-     *
-     * AND operator
-     *
-     * @param status, status to be AND.
-     * @return, the status after AND operation.
-     *
-     */
-    inline
-    Status operator&(Status &&s) const noexcept;
+    Status &
+    operator=(Status &&s);
 
-    /**
-     * @brief Status
-     *
-     * AND operator
-     *
-     * @param status, status to be AND.
-     * @return, the status after AND operation.
-     *
-     */
-    inline
-    Status &operator&=(const Status &s) noexcept;
-
-    /**
-     * @brief Status
-     *
-     * AND operator
-     *
-     * @param status, status to be AND.
-     * @return, the status after AND operation.
-     *
-     */
-    inline
-    Status &operator&=(Status &&s) noexcept;
-
-    /**
-     * @brief OK
-     *
-     * static OK status constructor
-     *
-     * @return, the status with OK.
-     *
-     */
-    static
-    Status OK() { return Status(); }
-
-    /**
-     * @brief OK
-     *
-     * static OK status constructor with a specific message
-     *
-     * @param, serveral specific messages
-     * @return, the status with OK.
-     *
-     */
-    template<typename... Args>
     static Status
-    OK(Args &&... args) {
-        return Status(StatusCode::OK, MessageBuilder(std::forward<Args>(args)...));
-    }
-
-/**
- * @brief Invalid
- *
- * static Invalid status constructor with a specific message
- *
- * @param, serveral specific messages
- * @return, the status with Invalid.
- *
- */
-template<typename... Args>
-static Status
-Invalid(Args &&... args) {
-    return Status(StatusCode::InvalidAgument,
-                  MessageBuilder(std::forward<Args>(args)...));
-}
-
-/**
- * @brief Unknown Error
- *
- * static unknown error status constructor with a specific message
- *
- * @param, serveral specific messages
- * @return, the status with unknown error.
- *
- */
-template<typename... Args>
-static Status
-UnknownError(Args &&... args) {
-    return Status(StatusCode::UnknownError, MessageBuilder(std::forward<Args>(args)...));
-}
-
-/**
- * @brief not supported Error
- *
- * static not supported status constructor with a specific message
- *
- * @param, serveral specific messages
- * @return, the status with not supported error.
- *
- */
-template<typename... Args>
-static Status
-NotSupported(Args &&... args) {
-    return Status(StatusCode::NotSupported, MessageBuilder(std::forward<Args>(args)...));
-}
-
-/**
- * @brief ok
- *
- * Return true iff the status indicates success.
- *
- * @return, if the status indicates success.
- *
- */
-bool
-ok() const { return (state_ == nullptr); }
-
-/**
- * @brief IsInvalid
- *
- * Return true iff the status indicates invalid.
- *
- * @return, if the status indicates invalid.
- *
- */
-bool
-IsInvalid() const { return code() == StatusCode::InvalidAgument; }
+    OK() { return Status(); }
 
-/**
- * @brief IsUnknownError
- *
- * Return true iff the status indicates unknown error.
- *
- * @return, if the status indicates unknown error.
- *
- */
-bool
-IsUnknownError() const { return code() == StatusCode::UnknownError; }
-
-/**
- * @brief IsNotSupported
- *
- * Return true iff the status indicates not supported.
- *
- * @return, if the status indicates not supported.
- *
- */
-bool
-IsNotSupported() const { return code() == StatusCode::NotSupported; }
-
-/**
- * @brief ToString
- *
- * Return error message string.
- *
- * @return, error message string.
- *
- */
-std::string
-ToString() const;
+    bool
+    ok() const { return state_ == nullptr || code() == StatusCode::OK; }
 
-/**
- * @brief CodeAsString
- *
- * Return a string representation of the status code.
- *
- * @return, a string representation of the status code.
- *
- */
-std::string
-CodeAsString() const;
-
-/**
- * @brief code
- *
- * Return the StatusCode value attached to this status.
- *
- * @return, the status code value attached to this status.
- *
- */
-StatusCode
-code() const { return ok() ? StatusCode::OK : state_->code; }
+    std::string
+    ToString() const;
 
-/**
- * @brief message
- *
- * Return the specific error message attached to this status.
- *
- * @return, the specific error message attached to this status.
- *
- */
-std::string
-message() const { return ok() ? "" : state_->message; }
+    ErrorCode
+    code() const {
+        return (state_ == nullptr) ? StatusCode::OK : *(ErrorCode*)(state_);
+    }
 
 private:
-struct State {
-    StatusCode code;
-    std::string message;
-};
-
-// OK status has a `nullptr` state_.  Otherwise, `state_` points to
-// a `State` structure containing the error code and message.
-State *state_ = nullptr;
-
-void
-DeleteState() {
-    delete state_;
-    state_ = nullptr;
-}
-
-void
-CopyFrom(const Status &s);
-
-inline void
-MoveFrom(Status &s);
+    inline void
+    CopyFrom(const Status &s);
 
-template<typename Head>
-static void
-MessageBuilderRecursive(std::stringstream &stream, Head &&head) {
-    stream << head;
-}
+    inline void
+    MoveFrom(Status &s);
 
-template<typename Head, typename... Tail>
-static void
-MessageBuilderRecursive(std::stringstream &stream, Head &&head, Tail &&... tail) {
-    MessageBuilderRecursive(stream, std::forward<Head>(head));
-    MessageBuilderRecursive(stream, std::forward<Tail>(tail)...);
-}
-
-template<typename... Args>
-static std::string
-MessageBuilder(Args &&... args) {
-    std::stringstream stream;
-
-    MessageBuilderRecursive(stream, std::forward<Args>(args)...);
+private:
+    const char *state_ = nullptr;
+}; // Status
 
-    return stream.str();
-}
-};
-}
\ No newline at end of file
+} //Milvus
\ No newline at end of file
diff --git a/cpp/src/sdk/interface/Status.cpp b/cpp/src/sdk/interface/Status.cpp
index 344d86c12f94c048e7e717425ed05b046825e45d..b04c6581feac1b7bb0ce3960ad84b8ee6e92bc7a 100644
--- a/cpp/src/sdk/interface/Status.cpp
+++ b/cpp/src/sdk/interface/Status.cpp
@@ -17,126 +17,113 @@
 
 #include "Status.h"
 
+#include <cstring>
+
 namespace milvus {
 
-Status::~Status() noexcept {
-    if (state_ != nullptr) {
-        delete state_;
-        state_ = nullptr;
-    }
+constexpr int CODE_WIDTH = sizeof(ErrorCode);
+
+Status::Status(ErrorCode code, const std::string& msg) {
+    //4 bytes store code
+    //4 bytes store message length
+    //the left bytes store message string
+    const uint32_t length = (uint32_t)msg.size();
+    char* result = new char[length + sizeof(length) + CODE_WIDTH];
+    memcpy(result, &code, CODE_WIDTH);
+    memcpy(result + CODE_WIDTH, &length, sizeof(length));
+    memcpy(result + sizeof(length) + CODE_WIDTH, msg.data(), length);
+
+    state_ = result;
 }
 
-static inline std::ostream &operator<<(std::ostream &os, const Status &x) {
-    os << x.ToString();
-    return os;
+Status::Status()
+        : state_(nullptr) {
+
 }
 
-void Status::MoveFrom(Status &s) {
+Status::~Status() {
     delete state_;
-    state_ = s.state_;
-    s.state_ = nullptr;
 }
 
 Status::Status(const Status &s)
-        : state_((s.state_ == nullptr) ? nullptr : new State(*s.state_)) {}
-
-Status::Status(Status &&s) noexcept {
-    MoveFrom(s);
+        : state_(nullptr) {
+    CopyFrom(s);
 }
 
 Status &Status::operator=(const Status &s) {
-    if (state_ != s.state_) {
-        CopyFrom(s);
-    }
+    CopyFrom(s);
     return *this;
 }
 
-Status &Status::operator=(Status &&s) noexcept {
+Status::Status(Status &&s)
+        : state_(nullptr) {
     MoveFrom(s);
-    return *this;
-}
-
-Status Status::operator&(const Status &status) const noexcept {
-    if (ok()) {
-        return status;
-    } else {
-        return *this;
-    }
 }
 
-Status Status::operator&(Status &&s) const noexcept {
-    if (ok()) {
-        return std::move(s);
-    } else {
-        return *this;
-    }
-}
-
-Status &Status::operator&=(const Status &s) noexcept {
-    if (ok() && !s.ok()) {
-        CopyFrom(s);
-    }
+Status &Status::operator=(Status &&s) {
+    MoveFrom(s);
     return *this;
 }
 
-Status &Status::operator&=(Status &&s) noexcept {
-    if (ok() && !s.ok()) {
-        MoveFrom(s);
+void Status::CopyFrom(const Status &s) {
+    delete state_;
+    state_ = nullptr;
+    if(s.state_ == nullptr) {
+        return;
     }
-    return *this;
-}
 
-Status::Status(StatusCode code, const std::string &message) {
-    state_ = new State;
-    state_->code = code;
-    state_->message = message;
+    uint32_t length = 0;
+    std::memcpy(&length, s.state_ + CODE_WIDTH, sizeof(length));
+    int buff_len = length + sizeof(length) + CODE_WIDTH;
+    state_ = new char[buff_len];
+    memcpy((void*)state_, (void*)s.state_, buff_len);
 }
 
-void Status::CopyFrom(const Status &status) {
+void Status::MoveFrom(Status &s) {
     delete state_;
-    if (status.state_ == nullptr) {
-        state_ = nullptr;
-    } else {
-        state_ = new State(*status.state_);
-    }
+    state_ = s.state_;
+    s.state_ = nullptr;
 }
 
-std::string Status::CodeAsString() const {
+std::string Status::ToString() const {
     if (state_ == nullptr) {
         return "OK";
     }
 
-    const char *type = nullptr;
+    std::string result;
     switch (code()) {
         case StatusCode::OK:
-            type = "OK";
-            break;
-        case StatusCode::InvalidAgument:
-            type = "Invalid agument";
+            result = "OK ";
             break;
         case StatusCode::UnknownError:
-            type = "Unknown error";
+            result = "Unknown error: ";
             break;
         case StatusCode::NotSupported:
-            type = "Not Supported";
+            result = "Not supported: ";
             break;
         case StatusCode::NotConnected:
-            type = "Not Connected";
+            result = "Not connected: ";
+            break;
+        case StatusCode::InvalidAgument:
+            result = "Invalid agument: ";
+            break;
+        case StatusCode::RPCFailed:
+            result = "Remote call failed: ";
+            break;
+        case StatusCode::ServerFailed:
+            result = "Service error: ";
             break;
         default:
-            type = "Unknown";
+            result = "Error code(" + std::to_string((int)code()) + "): ";
             break;
     }
-    return std::string(type);
-}
 
-std::string Status::ToString() const {
-    std::string result(CodeAsString());
-    if (state_ == nullptr) {
-        return result;
+    uint32_t length = 0;
+    memcpy(&length, state_ + CODE_WIDTH, sizeof(length));
+    if(length > 0) {
+        result.append(state_ + sizeof(length) + CODE_WIDTH, length);
     }
-    result += ": ";
-    result += state_->message;
+
     return result;
 }
 
diff --git a/cpp/src/sdk/util/Exception.h b/cpp/src/sdk/util/Exception.h
deleted file mode 100644
index f55b8f063272af1774f352b3c6ca96a54f0f9c0a..0000000000000000000000000000000000000000
--- a/cpp/src/sdk/util/Exception.h
+++ /dev/null
@@ -1,44 +0,0 @@
-// Licensed to the Apache Software Foundation (ASF) under one
-// or more contributor license agreements.  See the NOTICE file
-// distributed with this work for additional information
-// regarding copyright ownership.  The ASF licenses this file
-// to you under the Apache License, Version 2.0 (the
-// "License"); you may not use this file except in compliance
-// with the License.  You may obtain a copy of the License at
-//
-//   http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing,
-// software distributed under the License is distributed on an
-// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-// KIND, either express or implied.  See the License for the
-// specific language governing permissions and limitations
-// under the License.
-
-#pragma once
-
-#include "Status.h"
-
-#include <exception>
-
-namespace milvus {
-class Exception : public std::exception {
-public:
-    Exception(StatusCode error_code,
-            const std::string &message = std::string())
-        : error_code_(error_code), message_(message) {}
-
-public:
-    StatusCode error_code() const {
-        return error_code_;
-    }
-
-    virtual const char *what() const noexcept {
-        return message_.c_str();
-    }
-
-private:
-    StatusCode error_code_;
-    std::string message_;
-};
-}
\ No newline at end of file
diff --git a/cpp/src/server/grpc_impl/GrpcRequestTask.cpp b/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
index 8c7697e1dc5a0a9d0afd6a0243749cc0a276c17a..d7b39bea059d48a8d4df20af4e4e583827d94c1b 100644
--- a/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
+++ b/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
@@ -170,7 +170,7 @@ CreateTableTask::OnExecute() {
         table_info.metric_type_ = schema_->metric_type();
 
         //step 3: create table
-        engine::Status stat = DBWrapper::DB()->CreateTable(table_info);
+        auto stat = DBWrapper::DB()->CreateTable(table_info);
         if (!stat.ok()) {
             //table could exist
             if(stat.code() == DB_ALREADY_EXIST) {
@@ -214,7 +214,7 @@ DescribeTableTask::OnExecute() {
         //step 2: get table info
         engine::meta::TableSchema table_info;
         table_info.table_id_ = table_name_;
-        engine::Status stat = DBWrapper::DB()->DescribeTable(table_info);
+        auto stat = DBWrapper::DB()->DescribeTable(table_info);
         if (!stat.ok()) {
             return SetError(DB_META_TRANSACTION_FAILED, stat.ToString());
         }
@@ -261,7 +261,7 @@ CreateIndexTask::OnExecute() {
         }
 
         bool has_table = false;
-        engine::Status stat = DBWrapper::DB()->HasTable(table_name_, has_table);
+        auto stat = DBWrapper::DB()->HasTable(table_name_, has_table);
         if (!stat.ok()) {
             return SetError(DB_META_TRANSACTION_FAILED, stat.ToString());
         }
@@ -323,7 +323,7 @@ HasTableTask::OnExecute() {
         }
 
         //step 2: check table existence
-        engine::Status stat = DBWrapper::DB()->HasTable(table_name_, has_table_);
+        auto stat = DBWrapper::DB()->HasTable(table_name_, has_table_);
         if (!stat.ok()) {
             return SetError(DB_META_TRANSACTION_FAILED, stat.ToString());
         }
@@ -362,7 +362,7 @@ DropTableTask::OnExecute() {
         //step 2: check table existence
         engine::meta::TableSchema table_info;
         table_info.table_id_ = table_name_;
-        engine::Status stat = DBWrapper::DB()->DescribeTable(table_info);
+        auto stat = DBWrapper::DB()->DescribeTable(table_info);
         if (!stat.ok()) {
             if (stat.code() == DB_NOT_FOUND) {
                 return SetError(SERVER_TABLE_NOT_EXIST, "Table " + table_name_ + " not exists");
@@ -403,7 +403,7 @@ ShowTablesTask::Create(::grpc::ServerWriter<::milvus::grpc::TableName> *writer)
 ErrorCode
 ShowTablesTask::OnExecute() {
     std::vector<engine::meta::TableSchema> schema_array;
-    engine::Status stat = DBWrapper::DB()->AllTables(schema_array);
+    auto stat = DBWrapper::DB()->AllTables(schema_array);
     if (!stat.ok()) {
         return SetError(DB_META_TRANSACTION_FAILED, stat.ToString());
     }
@@ -460,7 +460,7 @@ InsertTask::OnExecute() {
         //step 2: check table existence
         engine::meta::TableSchema table_info;
         table_info.table_id_ = insert_param_->table_name();
-        engine::Status stat = DBWrapper::DB()->DescribeTable(table_info);
+        auto stat = DBWrapper::DB()->DescribeTable(table_info);
         if (!stat.ok()) {
             if (stat.code() == DB_NOT_FOUND) {
                 return SetError(SERVER_TABLE_NOT_EXIST,
@@ -599,7 +599,7 @@ SearchTask::OnExecute() {
         //step 2: check table existence
         engine::meta::TableSchema table_info;
         table_info.table_id_ = table_name_;
-        engine::Status stat = DBWrapper::DB()->DescribeTable(table_info);
+        auto stat = DBWrapper::DB()->DescribeTable(table_info);
         if (!stat.ok()) {
             if (stat.code() == DB_NOT_FOUND) {
                 return SetError(SERVER_TABLE_NOT_EXIST, "Table " + table_name_ + " not exists");
@@ -746,7 +746,7 @@ CountTableTask::OnExecute() {
 
         //step 2: get row count
         uint64_t row_count = 0;
-        engine::Status stat = DBWrapper::DB()->GetTableRowCount(table_name_, row_count);
+        auto stat = DBWrapper::DB()->GetTableRowCount(table_name_, row_count);
         if (!stat.ok()) {
             return SetError(DB_META_TRANSACTION_FAILED, stat.ToString());
         }
@@ -819,7 +819,7 @@ DeleteByRangeTask::OnExecute() {
         //step 2: check table existence
         engine::meta::TableSchema table_info;
         table_info.table_id_ = table_name;
-        engine::Status stat = DBWrapper::DB()->DescribeTable(table_info);
+        auto stat = DBWrapper::DB()->DescribeTable(table_info);
         if (!stat.ok()) {
             if (stat.code(), DB_NOT_FOUND) {
                 return SetError(SERVER_TABLE_NOT_EXIST, "Table " + table_name + " not exists");
@@ -846,8 +846,8 @@ DeleteByRangeTask::OnExecute() {
         std::string fname = "/tmp/search_nq_" + this->delete_by_range_param_->table_name() + ".profiling";
         ProfilerStart(fname.c_str());
 #endif
-        engine::Status status = DBWrapper::DB()->DeleteTable(table_name, dates);
-        if (!status.ok()) {
+        stat = DBWrapper::DB()->DeleteTable(table_name, dates);
+        if (!stat.ok()) {
             return SetError(DB_META_TRANSACTION_FAILED, stat.ToString());
         }
 
@@ -882,7 +882,7 @@ PreloadTableTask::OnExecute() {
         }
 
         //step 2: check table existence
-        engine::Status stat = DBWrapper::DB()->PreloadTable(table_name_);
+        auto stat = DBWrapper::DB()->PreloadTable(table_name_);
         if (!stat.ok()) {
             return SetError(DB_META_TRANSACTION_FAILED, stat.ToString());
         }
@@ -923,7 +923,7 @@ DescribeIndexTask::OnExecute() {
 
         //step 2: check table existence
         engine::TableIndex index;
-        engine::Status stat = DBWrapper::DB()->DescribeIndex(table_name_, index);
+        auto stat = DBWrapper::DB()->DescribeIndex(table_name_, index);
         if (!stat.ok()) {
             return SetError(DB_META_TRANSACTION_FAILED, stat.ToString());
         }
diff --git a/cpp/src/db/Status.cpp b/cpp/src/utils/Status.cpp
similarity index 64%
rename from cpp/src/db/Status.cpp
rename to cpp/src/utils/Status.cpp
index 0bc51ca59e8248b46f472f4ea5aacc6df394a6fa..0232c823f04ac9cebfd5331217f68a5b46455bc6 100644
--- a/cpp/src/db/Status.cpp
+++ b/cpp/src/utils/Status.cpp
@@ -14,15 +14,12 @@
 // KIND, either express or implied.  See the License for the
 // specific language governing permissions and limitations
 // under the License.
+#include "Status.h"
 
-#include <stdio.h>
 #include <cstring>
-#include <assert.h>
-#include "Status.h"
 
 namespace zilliz {
 namespace milvus {
-namespace engine {
 
 constexpr int CODE_WIDTH = sizeof(ErrorCode);
 
@@ -45,55 +42,87 @@ Status::Status()
 }
 
 Status::~Status() {
-    delete[] state_;
+    delete state_;
+}
+
+Status::Status(const Status &s)
+    : state_(nullptr) {
+    CopyFrom(s);
 }
 
-const char* Status::CopyState(const char* state) {
+Status &Status::operator=(const Status &s) {
+    CopyFrom(s);
+    return *this;
+}
+
+Status::Status(Status &&s)
+    : state_(nullptr) {
+    MoveFrom(s);
+}
+
+Status &Status::operator=(Status &&s) {
+    MoveFrom(s);
+    return *this;
+}
+
+void Status::CopyFrom(const Status &s) {
+    delete state_;
+    state_ = nullptr;
+    if(s.state_ == nullptr) {
+        return;
+    }
+
     uint32_t length = 0;
-    std::memcpy(&length, state + CODE_WIDTH, sizeof(length));
+    std::memcpy(&length, s.state_ + CODE_WIDTH, sizeof(length));
     int buff_len = length + sizeof(length) + CODE_WIDTH;
-    char* result = new char[buff_len];
-    memcpy(result, state, buff_len);
-    return result;
+    state_ = new char[buff_len];
+    memcpy((void*)state_, (void*)s.state_, buff_len);
+}
+
+void Status::MoveFrom(Status &s) {
+    delete state_;
+    state_ = s.state_;
+    s.state_ = nullptr;
 }
 
 std::string Status::ToString() const {
-    if (state_ == nullptr) return "OK";
-    char tmp[32];
-    const char* type;
+    if (state_ == nullptr) {
+        return "OK";
+    }
+
+    std::string result;
     switch (code()) {
         case DB_SUCCESS:
-            type = "OK";
+            result = "OK ";
             break;
         case DB_ERROR:
-            type = "Error: ";
+            result = "Error: ";
             break;
         case DB_META_TRANSACTION_FAILED:
-            type = "DBTransactionError: ";
+            result = "Database error: ";
             break;
         case DB_NOT_FOUND:
-            type = "NotFound: ";
+            result = "Not found: ";
             break;
         case DB_ALREADY_EXIST:
-            type = "AlreadyExist: ";
+            result = "Already exist: ";
             break;
         case DB_INVALID_PATH:
-            type = "InvalidPath: ";
+            result = "Invalid path: ";
             break;
         default:
-            snprintf(tmp, sizeof(tmp), "Error code(0x%x): ",
-                    static_cast<int>(code()));
-            type = tmp;
+            result = "Error code(" + std::to_string(code()) + "): ";
             break;
     }
 
-    std::string result(type);
     uint32_t length = 0;
     memcpy(&length, state_ + CODE_WIDTH, sizeof(length));
-    result.append(state_ + sizeof(length) + CODE_WIDTH, length);
+    if(length > 0) {
+        result.append(state_ + sizeof(length) + CODE_WIDTH, length);
+    }
+
     return result;
 }
 
-} // namespace engine
 } // namespace milvus
 } // namespace zilliz
diff --git a/cpp/src/db/Status.h b/cpp/src/utils/Status.h
similarity index 55%
rename from cpp/src/db/Status.h
rename to cpp/src/utils/Status.h
index e3dae4c0adc3d8eddad1403f2c42c622e063243e..153ff61dc5383c17f0bbe0ceea60fbc82dda7b73 100644
--- a/cpp/src/db/Status.h
+++ b/cpp/src/utils/Status.h
@@ -15,6 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
+
 #pragma once
 
 #include "utils/Error.h"
@@ -23,7 +24,6 @@
 
 namespace zilliz {
 namespace milvus {
-namespace engine {
 
 class Status {
  public:
@@ -31,51 +31,40 @@ class Status {
     Status();
     ~Status();
 
-    Status(const Status &rhs);
+    Status(const Status &s);
 
     Status &
-    operator=(const Status &rhs);
+    operator=(const Status &s);
 
-    Status(Status &&rhs) noexcept : state_(rhs.state_) { rhs.state_ = nullptr; }
+    Status(Status &&s);
 
     Status &
-    operator=(Status &&rhs_) noexcept;
+    operator=(Status &&s);
 
     static Status
     OK() { return Status(); }
 
-    bool ok() const { return state_ == nullptr || code() == DB_SUCCESS; }
+    bool
+    ok() const { return state_ == nullptr || code() == 0; }
 
-    std::string ToString() const;
+    std::string
+    ToString() const;
 
-    ErrorCode code() const {
-        return (state_ == nullptr) ? DB_SUCCESS : *(ErrorCode*)(state_);
+    ErrorCode
+    code() const {
+        return (state_ == nullptr) ? 0 : *(ErrorCode*)(state_);
     }
 
- private:
-    const char *state_ = nullptr;
+private:
+    inline void
+    CopyFrom(const Status &s);
 
-    static const char *CopyState(const char *s);
+    inline void
+    MoveFrom(Status &s);
 
+private:
+    const char *state_ = nullptr;
 }; // Status
 
-inline Status::Status(const Status &rhs) {
-    state_ = (rhs.state_ == nullptr) ? nullptr : CopyState(rhs.state_);
-}
-
-inline Status &Status::operator=(const Status &rhs) {
-    if (state_ != rhs.state_) {
-        delete[] state_;
-        state_ = (rhs.state_ == nullptr) ? nullptr : CopyState(rhs.state_);
-    }
-    return *this;
-}
-
-inline Status &Status::operator=(Status &&rhs) noexcept {
-    std::swap(state_, rhs.state_);
-    return *this;
-}
-
-} // namespace engine
 } // namespace milvus
 } // namespace zilliz
diff --git a/cpp/unittest/db/CMakeLists.txt b/cpp/unittest/db/CMakeLists.txt
index 00b6f64dbf5ceca00660033eb2eb097ca9b23737..29440dcf1a0412a7fc7904030274e5fd74391d16 100644
--- a/cpp/unittest/db/CMakeLists.txt
+++ b/cpp/unittest/db/CMakeLists.txt
@@ -33,9 +33,9 @@ aux_source_directory(${MILVUS_ENGINE_SRC}/scheduler scheduler_srcs)
 aux_source_directory(./ test_srcs)
 
 set(util_files
+        ${MILVUS_ENGINE_SRC}/utils/Status.cpp
         ${MILVUS_ENGINE_SRC}/utils/ValidationUtil.cpp
-        ${MILVUS_ENGINE_SRC}/utils/easylogging++.cc
-        ${MILVUS_ENGINE_SRC}/utils/easylogging++.h)
+        ${MILVUS_ENGINE_SRC}/utils/easylogging++.cc)
 
 aux_source_directory(${MILVUS_ENGINE_SRC}/db/scheduler scheduler_files)
 aux_source_directory(${MILVUS_ENGINE_SRC}/db/scheduler/context scheduler_context_files)
diff --git a/cpp/unittest/db/db_tests.cpp b/cpp/unittest/db/db_tests.cpp
index 372dd336d6b5c7aa4fba636c1254d7c68b2a0d45..a1fd14a8f410e3a671674b34c1d69ab7b0f0a257 100644
--- a/cpp/unittest/db/db_tests.cpp
+++ b/cpp/unittest/db/db_tests.cpp
@@ -154,7 +154,7 @@ TEST_F(DBTest, CONFIG_TEST) {
 
 TEST_F(DBTest, DB_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -230,7 +230,7 @@ TEST_F(DBTest, DB_TEST) {
 
 TEST_F(DBTest, SEARCH_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -296,7 +296,7 @@ TEST_F(DBTest, SEARCH_TEST) {
 
 TEST_F(DBTest, PRELOADTABLE_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -331,7 +331,7 @@ TEST_F(DBTest, SHUTDOWN_TEST) {
     db_->Stop();
 
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
     ASSERT_FALSE(stat.ok());
 
     stat = db_->DescribeTable(table_info);
@@ -373,7 +373,7 @@ TEST_F(DBTest, SHUTDOWN_TEST) {
 
 TEST_F(DBTest, INDEX_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     int64_t nb = VECTOR_COUNT;
     std::vector<float> xb;
@@ -403,7 +403,7 @@ TEST_F(DBTest, INDEX_TEST) {
 TEST_F(DBTest2, ARHIVE_DISK_CHECK) {
 
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     std::vector<engine::meta::TableSchema> table_schema_array;
     stat = db_->AllTables(table_schema_array);
@@ -446,7 +446,7 @@ TEST_F(DBTest2, ARHIVE_DISK_CHECK) {
 
 TEST_F(DBTest2, DELETE_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -480,7 +480,7 @@ TEST_F(DBTest2, DELETE_TEST) {
 
 TEST_F(DBTest2, DELETE_BY_RANGE_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
diff --git a/cpp/unittest/db/mem_test.cpp b/cpp/unittest/db/mem_test.cpp
index 73f6d89f5e81c62ac51d8bd794d856de030dd5dd..4e958795ad84461ced5030aadf95cd7baf14c85f 100644
--- a/cpp/unittest/db/mem_test.cpp
+++ b/cpp/unittest/db/mem_test.cpp
@@ -216,7 +216,7 @@ TEST_F(MemManagerTest, MEM_TABLE_TEST) {
 
 TEST_F(MemManagerTest2, SERIAL_INSERT_SEARCH_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -230,8 +230,8 @@ TEST_F(MemManagerTest2, SERIAL_INSERT_SEARCH_TEST) {
         int64_t nb = 100000;
         std::vector<float> xb;
         BuildVectors(nb, xb);
-        engine::Status status = db_->InsertVectors(TABLE_NAME, nb, xb.data(), vector_ids);
-        ASSERT_TRUE(status.ok());
+        stat = db_->InsertVectors(TABLE_NAME, nb, xb.data(), vector_ids);
+        ASSERT_TRUE(stat.ok());
 
         std::this_thread::sleep_for(std::chrono::seconds(3));
 
@@ -262,7 +262,7 @@ TEST_F(MemManagerTest2, SERIAL_INSERT_SEARCH_TEST) {
 
 TEST_F(MemManagerTest2, INSERT_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -278,8 +278,8 @@ TEST_F(MemManagerTest2, INSERT_TEST) {
         std::vector<float> xb;
         BuildVectors(nb, xb);
         engine::IDNumbers vector_ids;
-        engine::Status status = db_->InsertVectors(TABLE_NAME, nb, xb.data(), vector_ids);
-        ASSERT_TRUE(status.ok());
+        stat = db_->InsertVectors(TABLE_NAME, nb, xb.data(), vector_ids);
+        ASSERT_TRUE(stat.ok());
     }
     auto end_time = METRICS_NOW_TIME;
     auto total_time = METRICS_MICROSECONDS(start_time, end_time);
@@ -288,7 +288,7 @@ TEST_F(MemManagerTest2, INSERT_TEST) {
 
 TEST_F(MemManagerTest2, CONCURRENT_INSERT_SEARCH_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -359,7 +359,7 @@ TEST_F(MemManagerTest2, CONCURRENT_INSERT_SEARCH_TEST) {
 
 TEST_F(MemManagerTest2, VECTOR_IDS_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
diff --git a/cpp/unittest/db/misc_test.cpp b/cpp/unittest/db/misc_test.cpp
index 28ec0f2f9c93dc04ba8e710862c2533f491dcaf9..ff530b0a734c5a172aaee1bd9f0e3ed1913a816c 100644
--- a/cpp/unittest/db/misc_test.cpp
+++ b/cpp/unittest/db/misc_test.cpp
@@ -15,11 +15,11 @@
 // specific language governing permissions and limitations
 // under the License.
 
-#include "db/Status.h"
 #include "db/Options.h"
 #include "db/meta/SqliteMetaImpl.h"
 #include "db/engine/EngineFactory.h"
 #include "db/Utils.h"
+#include "utils/Status.h"
 #include "utils/Exception.h"
 #include "utils/easylogging++.h"
 
@@ -30,13 +30,6 @@
 
 using namespace zilliz::milvus;
 
-namespace {
-    void CopyStatus(engine::Status& st1, engine::Status& st2) {
-        st1 = st2;
-    }
-
-}
-
 TEST(DBMiscTest, EXCEPTION_TEST) {
     Exception ex1("");
     std::string what = ex1.what();
@@ -47,36 +40,6 @@ TEST(DBMiscTest, EXCEPTION_TEST) {
     ASSERT_FALSE(what.empty());
 }
 
-TEST(DBMiscTest, STATUS_TEST) {
-    engine::Status status = engine::Status::OK();
-    std::string str = status.ToString();
-    ASSERT_FALSE(str.empty());
-
-    status = engine::Status(DB_ERROR, "mistake");
-    ASSERT_EQ(status.code(), DB_ERROR);
-    str = status.ToString();
-    ASSERT_FALSE(str.empty());
-
-    status = engine::Status(DB_NOT_FOUND, "mistake");
-    ASSERT_EQ(status.code(), DB_NOT_FOUND);
-    str = status.ToString();
-    ASSERT_FALSE(str.empty());
-
-    status = engine::Status(DB_ALREADY_EXIST, "mistake");
-    ASSERT_EQ(status.code(), DB_ALREADY_EXIST);
-    str = status.ToString();
-    ASSERT_FALSE(str.empty());
-
-    status = engine::Status(DB_META_TRANSACTION_FAILED, "mistake");
-    ASSERT_EQ(status.code(), DB_META_TRANSACTION_FAILED);
-    str = status.ToString();
-    ASSERT_FALSE(str.empty());
-
-    engine::Status status_copy = engine::Status::OK();
-    CopyStatus(status_copy, status);
-    ASSERT_EQ(status.code(), DB_META_TRANSACTION_FAILED);
-}
-
 TEST(DBMiscTest, OPTIONS_TEST) {
     try {
         engine::ArchiveConf archive("$$##");
diff --git a/cpp/unittest/db/mysql_db_test.cpp b/cpp/unittest/db/mysql_db_test.cpp
index 35f086b0338be38134c25fc54cb1b83313a6e5be..9d99b4095becd4528ab7f2a19e6a0114eaf77c8a 100644
--- a/cpp/unittest/db/mysql_db_test.cpp
+++ b/cpp/unittest/db/mysql_db_test.cpp
@@ -59,7 +59,7 @@ namespace {
 
 TEST_F(MySqlDBTest, DB_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -144,7 +144,7 @@ TEST_F(MySqlDBTest, DB_TEST) {
 
 TEST_F(MySqlDBTest, SEARCH_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     engine::meta::TableSchema table_info_get;
     table_info_get.table_id_ = TABLE_NAME;
@@ -196,7 +196,7 @@ TEST_F(MySqlDBTest, SEARCH_TEST) {
 
 TEST_F(MySqlDBTest, ARHIVE_DISK_CHECK) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 
     std::vector<engine::meta::TableSchema> table_schema_array;
     stat = db_->AllTables(table_schema_array);
@@ -241,7 +241,7 @@ TEST_F(MySqlDBTest, ARHIVE_DISK_CHECK) {
 
 TEST_F(MySqlDBTest, DELETE_TEST) {
     engine::meta::TableSchema table_info = BuildTableSchema();
-    engine::Status stat = db_->CreateTable(table_info);
+    auto stat = db_->CreateTable(table_info);
 //    std::cout << stat.ToString() << std::endl;
 
     engine::meta::TableSchema table_info_get;
diff --git a/cpp/unittest/metrics/CMakeLists.txt b/cpp/unittest/metrics/CMakeLists.txt
index 07f27e1e67ef443f688e1398ab44b137f2e9e5f3..dddba2906a7129284fcb04ac6a644f45028ce5d7 100644
--- a/cpp/unittest/metrics/CMakeLists.txt
+++ b/cpp/unittest/metrics/CMakeLists.txt
@@ -37,9 +37,9 @@ aux_source_directory(${MILVUS_ENGINE_SRC}/src/metrics metrics_src)
 aux_source_directory(./ test_srcs)
 
 set(util_files
+        ${MILVUS_ENGINE_SRC}/utils/Status.cpp
         ${MILVUS_ENGINE_SRC}/utils/ValidationUtil.cpp
-        ${MILVUS_ENGINE_SRC}/utils/easylogging++.cc
-        ${MILVUS_ENGINE_SRC}/utils/easylogging++.h)
+        ${MILVUS_ENGINE_SRC}/utils/easylogging++.cc)
 
 aux_source_directory(${MILVUS_ENGINE_SRC}/db/scheduler scheduler_files)
 aux_source_directory(${MILVUS_ENGINE_SRC}/db/scheduler/context scheduler_context_files)
diff --git a/cpp/unittest/metrics/metrics_test.cpp b/cpp/unittest/metrics/metrics_test.cpp
index 2bd06ed091dce45f3079b8f2be9b3d9095befc8f..636e2ffbb1950d74a6f64a4cf3b11cfb450a14e8 100644
--- a/cpp/unittest/metrics/metrics_test.cpp
+++ b/cpp/unittest/metrics/metrics_test.cpp
@@ -57,7 +57,7 @@ TEST_F(MetricTest, METRIC_TEST) {
     engine::meta::TableSchema group_info;
     group_info.dimension_ = group_dim;
     group_info.table_id_ = group_name;
-    engine::Status stat = db_->CreateTable(group_info);
+    auto stat = db_->CreateTable(group_info);
 
     engine::meta::TableSchema group_info_get;
     group_info_get.table_id_ = group_name;
@@ -134,9 +134,9 @@ TEST_F(MetricTest, METRIC_TEST) {
 };
 
 TEST_F(MetricTest, COLLECTOR_METRICS_TEST){
-    engine::Status status = engine::Status::OK();
+    auto status = Status::OK();
     server::CollectInsertMetrics insert_metrics0(0, status);
-    status = engine::Status(DB_ERROR, "error");
+    status = Status(DB_ERROR, "error");
     server::CollectInsertMetrics insert_metrics1(0, status);
 
     server::CollectQueryMetrics query_metrics(10);
diff --git a/cpp/unittest/metrics/utils.h b/cpp/unittest/metrics/utils.h
index ef25654ed034003f38198f9bc9e05ea5937c57ee..7f093dd0913ab10feb1fa0c9f8914a2e17916d4e 100644
--- a/cpp/unittest/metrics/utils.h
+++ b/cpp/unittest/metrics/utils.h
@@ -42,7 +42,7 @@
 #define STOP_TIMER(name)
 #endif
 
-void ASSERT_STATS(zilliz::milvus::engine::Status& stat);
+void ASSERT_STATS(zilliz::milvus::Status& stat);
 
 //class TestEnv : public ::testing::Environment {
 //public:
diff --git a/cpp/unittest/scheduler/CMakeLists.txt b/cpp/unittest/scheduler/CMakeLists.txt
index 9ada727f8eff6d0cbc14a2d628e4bf5d6bc445d5..7359420e16819bd66f37549714e3a374a1bc86d1 100644
--- a/cpp/unittest/scheduler/CMakeLists.txt
+++ b/cpp/unittest/scheduler/CMakeLists.txt
@@ -36,9 +36,9 @@ aux_source_directory(${MILVUS_ENGINE_SRC}/scheduler scheduler_srcs)
 aux_source_directory(./ test_srcs)
 
 set(util_files
+        ${MILVUS_ENGINE_SRC}/utils/Status.cpp
         ${MILVUS_ENGINE_SRC}/utils/ValidationUtil.cpp
-        ${MILVUS_ENGINE_SRC}/utils/easylogging++.cc
-        ${MILVUS_ENGINE_SRC}/utils/easylogging++.h)
+        ${MILVUS_ENGINE_SRC}/utils/easylogging++.cc)
 
 set(db_scheduler_srcs
         ${scheduler_files}
diff --git a/cpp/unittest/server/CMakeLists.txt b/cpp/unittest/server/CMakeLists.txt
index 6bbe2183ce604f475c9d66dc85c36a7f26795858..8e0685992992c9145eb5b6c7cc09519df81aea2c 100644
--- a/cpp/unittest/server/CMakeLists.txt
+++ b/cpp/unittest/server/CMakeLists.txt
@@ -54,9 +54,9 @@ set(db_scheduler_srcs
         )
 
 set(util_files
+        ${MILVUS_ENGINE_SRC}/utils/Status.cpp
         ${MILVUS_ENGINE_SRC}/utils/ValidationUtil.cpp
-        ${MILVUS_ENGINE_SRC}/utils/easylogging++.cc
-        ${MILVUS_ENGINE_SRC}/utils/easylogging++.h)
+        ${MILVUS_ENGINE_SRC}/utils/easylogging++.cc)
 
 set(db_src
         ${config_files}
diff --git a/cpp/unittest/server/util_test.cpp b/cpp/unittest/server/util_test.cpp
index 3849f79d19a965fdd1a1078ef4bf4faeeefc3f24..cfbcbab683320fa64bc0ffb315023fbe5bd09139 100644
--- a/cpp/unittest/server/util_test.cpp
+++ b/cpp/unittest/server/util_test.cpp
@@ -37,6 +37,10 @@ namespace {
 
 static const char* LOG_FILE_PATH = "./milvus/conf/log_config.conf";
 
+void CopyStatus(Status& st1, Status& st2) {
+    st1 = st2;
+}
+
 }
 
 TEST(UtilTest, EXCEPTION_TEST) {
@@ -183,6 +187,44 @@ TEST(UtilTest, TIMERECORDER_TEST) {
     }
 }
 
+TEST(UtilTest, STATUS_TEST) {
+    auto status = Status::OK();
+    std::string str = status.ToString();
+    ASSERT_FALSE(str.empty());
+
+    status = Status(DB_ERROR, "mistake");
+    ASSERT_EQ(status.code(), DB_ERROR);
+    str = status.ToString();
+    ASSERT_FALSE(str.empty());
+
+    status = Status(DB_NOT_FOUND, "mistake");
+    ASSERT_EQ(status.code(), DB_NOT_FOUND);
+    str = status.ToString();
+    ASSERT_FALSE(str.empty());
+
+    status = Status(DB_ALREADY_EXIST, "mistake");
+    ASSERT_EQ(status.code(), DB_ALREADY_EXIST);
+    str = status.ToString();
+    ASSERT_FALSE(str.empty());
+
+    status = Status(DB_META_TRANSACTION_FAILED, "mistake");
+    ASSERT_EQ(status.code(), DB_META_TRANSACTION_FAILED);
+    str = status.ToString();
+    ASSERT_FALSE(str.empty());
+
+    auto status_copy = Status::OK();
+    CopyStatus(status_copy, status);
+    ASSERT_EQ(status.code(), DB_META_TRANSACTION_FAILED);
+
+    auto status_ref(status);
+    ASSERT_EQ(status_ref.code(), status.code());
+    ASSERT_EQ(status_ref.ToString(), status.ToString());
+
+    auto status_move = std::move(status);
+    ASSERT_EQ(status_move.code(), status_ref.code());
+    ASSERT_EQ(status_move.ToString(), status_ref.ToString());
+}
+
 TEST(ValidationUtilTest, VALIDATE_TABLENAME_TEST) {
     std::string table_name = "Normal123_";
     ErrorCode res = server::ValidationUtil::ValidateTableName(table_name);